This invention relates to a grinding apparatus, and more particularly, a kitchen-type appliance for grinding a knife edge to sharpen the same.
Knife sharpening devices have been known and used heretofore. Such devices are usually manufactured with non-replaceable parts. Accordingly, should the grinding or sharpening elements become worn, and they will after extended use, the device will no longer perform its function and must be thrown away and replaced. The knife sharpening device of the present invention provides another option.
In accordance with the construction of the present invention, a pair of grinding wheels are provided beneath a slot in the device housing which receives the edge of a knife to be sharpened. Each grinding wheel is connected to a shaft or spindle housed within a tube. A coil spring bears against the end of the shaft or spindle of the grinding wheel and biases it forwardly towards the other grinding wheel which is similarly supported at an inclined angle to the horizontal beneath the knife receiving slot. As the knife passes through the slot, it will contact each of the inclined faces of the side-by-side grinding wheels, causing each wheel to move rearwardly against the bias of the coil spring in its tube. When the knife edge is appropriately seated between the wheels, whose circumferences are designed to overlap slightly when extended, the knife edge will be firmly clamped between each of the grinding wheels. Backward and forward motion through the transversely slot across the axis of each grinding wheel spindle will cause the grinding wheels to rotate at an angle against the lower edge of the knife to grind and sharpen the same.
A roller can be located on opposite sides of the grinding wheels for providing a friction-free surface upon which the knife edge being sharpened can be readily slid in the slot relative to the grinding wheels.
The grinding wheel shafts or spindles are housed within a tube which is replaceably supported on the inclined surface of a support block encased within a substantially rectangular parallelopiped housing. The housing is threadably fastened to the support block and includes downwardly extending portions which contact each of the spindle receiving tubes to firmly lock the tube in place on the support block. Upon disassembly of the housing and support block, by removal of the threaded fasteners, each of the spindle receiving tubes can be removed from the support block along with each grinding wheel. The grinding wheels can then be removed from their support tubes and replaced and the entire assembly then reconnected, with the replacement parts readily intact.